U.S. patent application number 14/664974 was filed with the patent office on 2015-12-31 for activated films having low sound pressure levels.
The applicant listed for this patent is The Procter & Gamble Company. Invention is credited to Clarissa MALDONADO.
Application Number | 20150376384 14/664974 |
Document ID | / |
Family ID | 54929805 |
Filed Date | 2015-12-31 |
United States Patent
Application |
20150376384 |
Kind Code |
A1 |
MALDONADO; Clarissa |
December 31, 2015 |
ACTIVATED FILMS HAVING LOW SOUND PRESSURE LEVELS
Abstract
A film comprising from about 20 wt. % to about 85 wt. % of a
polyolefin component and from about 20 wt. % to about 45 wt. % of a
particle component; wherein the film has a basis weight of from
about 5 gsm to about 25 gsm; wherein the film is activated and
subjected to an engineering strain of greater than about 20%;
wherein the film has a predicted sound pressure level over the
frequency octave range of 2000 Hz-6300 Hz of less than about 43
dB.
Inventors: |
MALDONADO; Clarissa;
(Cincinnati, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Procter & Gamble Company |
Cincinnati |
OH |
US |
|
|
Family ID: |
54929805 |
Appl. No.: |
14/664974 |
Filed: |
March 23, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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62017576 |
Jun 26, 2014 |
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Current U.S.
Class: |
604/367 ;
428/219 |
Current CPC
Class: |
A61F 13/514 20130101;
A61F 13/551 20130101; A61L 15/54 20130101; C08K 2003/2237 20130101;
A61F 13/51456 20130101; C08J 5/18 20130101; C08L 23/06 20130101;
A61L 15/225 20130101; A61F 13/51401 20130101; A61L 15/225 20130101;
A61L 15/42 20130101; C08J 2323/04 20130101; A61L 15/00 20130101;
C08L 23/06 20130101; A61F 13/15 20130101; C08J 2423/14 20130101;
A61F 13/51464 20130101; C08K 3/26 20130101; A61F 13/51462 20130101;
C08K 3/22 20130101; C08K 2003/265 20130101 |
International
Class: |
C08L 23/06 20060101
C08L023/06; C08K 3/22 20060101 C08K003/22; A61L 15/22 20060101
A61L015/22; C08K 3/26 20060101 C08K003/26 |
Claims
1. A film comprising: a. from about 20 wt. % to about 85 wt. % of a
polyolefin component; and b. from about 20 wt. % to about 45 wt. %
of a particle component; wherein the film has a basis weight of
from about 5 gsm to about 25 gsm prior to activation; wherein the
film is activated and subjected to an engineering strain of greater
than about 20%; wherein the film has a predicted sound pressure
level over the frequency octave range of 2000 Hz-6300 Hz of less
than about 43 dB.
2. The film of claim 1, wherein the basis weight is from about 13
gsm to about 20 gsm.
3. The film of claim 1, wherein the polyolefin component is
selected from the group consisting of linear low density
polyethylene polymers, low density polyethylene polymers, high
density polyethylene polymers, polypropylene polymers, and mixtures
thereof.
4. The film of claim 1, wherein the polyolefin component is
selected from the group consisting of linear low density
polyethylene polymers and low density polyethylene polymers.
5. The film of claim 1, wherein the polyolefin component has a
density of from about 0.91 g/cm3 to about 0.95 g/cm3
6. The film of claim 1, further comprising from about 1 wt. % to
about 30 wt. % of an elastomeric resin.
7. The film of claim 1, further comprising less than about 15 wt. %
of an elastomeric resin.
8. The film of claim 7, wherein the elastomeric resin is selected
from the group consisting of propylene based elastomer, propylene
ethylene copolymer, and styrenic block copolymer resin.
9. The film of claim 7, wherein the elastomeric resin is a
propylene based elastomer.
10. The film of claim 7, wherein the elastomeric resin has a degree
of crystallinity or end block content of from about 5% to about
33%.
11. The film of claim 1, comprising from about 25 wt. % to about 40
wt. % of the particle component.
12. The film of claim 1, wherein the particle component is selected
from the group consisting of friction reducing particles and
opacifier particles.
13. The film of claim 1, wherein the particle component is selected
from the group consisting of CaCO3, TiO2, and combinations
thereof.
14. The film of claim 1, wherein the particle component has a
density of from about 1.8 g/cm3 to about 4.5 g/cm3.
15. The film of claim 1, wherein the particle component has a
density of at least about 2 times the density of the polyolefin
component.
16. The film of claim 1, wherein the film is activated with a 1.52
mm pitch tooling such that the depth of engagement of the tooling
is from about 0.508 mm to about 1.27 mm.
17. The film of claim 1, wherein the film is subjected to an
engineering strain of from about 20% to about 70%.
18. The film of claim 1, wherein the film has a predicted sound
pressure level over the frequency octave range of 2000 Hz-6300 Hz
of less than about 40 dB.
19. A film comprising: a. from about 20 wt. % to about 85 wt. % of
a polyolefin component; b. less than about 15 wt. % of an
elastomeric resin; and c. from about 20 wt. % to about 45 wt. % of
a particle component; wherein the film has a basis weight of from
about 5 gsm to about 25 gsm prior to activation; wherein the film
is activated and subjected to an engineering strain of from about
24% to about 85%; wherein the film has a predicted sound pressure
level over the frequency octave range of 2000 Hz-6300 Hz of less
than about 40 dB.
20. The film of claim 1, wherein the film is incorporated in an
absorbent article selected from the group consisting of a diaper, a
pant, an absorbent insert for a diaper or pant, a sanitary napkin,
and a pantiliner.
21. The film of claim 1, wherein the film is incorporated in a
package or wrapper.
22. The film of claim 1, wherein the film is incorporated in a
component of an absorbent article selected from the group
consisting of backsheet, waistband, fastening members, and ears.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a film comprising a
polyolefin component and a particle component. The film has a basis
weight of from about 5 gsm to about 25 gsm. The film is activated
and subjected to an engineering strain of greater than about 20%.
The film has a predicted sound pressure level over the frequency
octave range of 2000 Hz-6300 Hz of less than about 43 dB.
BACKGROUND OF THE INVENTION
[0002] Films are commonly used as barriers. Some films are
engineered to be liquid impervious and moisture impervious such as
those used as protective packages or those used in absorbent
products. Other films are engineered to be liquid impervious and
moisture permeable such as those used in diapers or adult
incontinence products.
[0003] In some instances, it may be desirable for the product or
package to not produce a lot of noises. It is desirable for
products such as feminine pads, incontinence products, tampons, and
their packaging to be discrete, therefore it is preferred that
these products and packages generate the lowest amount of noise
possible. Other products like diapers and premium packages seek to
mimic the appearance and feel of cloth, therefore plastic sounding
materials are less desirable.
[0004] Sound is the result of a vibrating object pushing the air
surrounding it and creating bands of high and low pressure. These
bands of high and low pressure are longitudinal waves that the
human ear perceives as sound. Each sound can be described by a
magnitude, known as sound pressure level measured in decibels (dB)
and a frequency which is measured in hertz (Hz). The human auditory
system is most sensitive from 2,000 to 5,000 Hz due to the
resonance of the ear canal. An object vibrates as a result of an
input force of a certain magnitude and frequency and the mass,
stiffness and damping characteristics of the object. One way to
reduce the noise generated by a product containing a film is to
reduce the noise produced by the film. This can be achieved by
reducing the film stiffness, increasing its mass or changing its
damping characteristics.
[0005] The stiffness of an elastic film is calculated using the
Young's modulus E of the film. The Young's modulus is the slope of
the stress strain curve at the strains of interest. Typically,
films are anisotropic, therefore they will have different Young's
modulus depending on the tensile test direction. The speed at which
the tensile test is conducted will also impact the resulting
modulus. The measurements should be taken at speeds relevant to the
application.
[0006] The strain levels that vibrating thin polyolefin films
experience are small and in most cases below the yield point of the
film. Therefore the strains considered when calculating Young's
modulus are between 0.01 and 0.05.
[0007] The extrusion and processing conditions under which a film
is produced will impact the level of crystallization on the film
which in turn will affect the resulting modulus and noise produced
by the film. For example, in cast extrusion processes the
temperature of the casting roll, chill rolls temperatures and
arrangements, melt temperature, take off-speed and annealing roll
temperature will affect the level of crystallization on the film
and may impact the film stiffness and noise.
[0008] Polymer structures can be anywhere from 5% to 95%
crystalline. In addition to extrusion processing conditions, the
level of crystallinity will also depend on the simplicity of the
chain structure, chemistry, side branching and whether the polymer
is isotactic, syndiotactic or atactic. Some of the known methods
used to measure the amount of crystallinity in a polymer make use
of Differential Scanning calorimetry, X-Ray Diffraction or by a
density measurement if the density of the crystal phase and
amorphous phases are known. The more crystalline the polymer
structure, the higher the Young's modulus and the noise produced by
the resulting film. For example: Resin blends with higher content
of resins with higher side branching such as Low Density
Polyethylene are preferred as their typical degree of crystallinity
is 45-55%. Less content of polymers with chain regularity is
preferred such as isotactic polypropylene which typical degree of
crystallinity is 70%-80%.
[0009] Incremental stretching of thermoplastic film typically
involves running the film between grooved or toothed rollers. The
grooves or teeth on the rollers intermesh and stretch the film as
the film passes between the rollers. Incremental stretch can
stretch a film in many small increments that are evenly spaced
across the film. The depth at which the intermeshing teeth engage
can control the degree of stretching. One type of incremental
stretching is referred to as ring-rolling.
[0010] Therefore, it is an object of the present invention to
produce films that have a predicted sound pressure level over the
frequency octave range of 2000 Hz-6300 Hz of less than about 43
dB.
SUMMARY OF THE INVENTION
[0011] The present invention is directed to a film comprising from
about 20 wt. % to about 85 wt. % of a polyolefin component and from
about 20 wt. % to about 45 wt. % of a particle component. The film
of the present invention has a basis weight of from about 5 gsm to
about 25 gsm prior to activation. The film is activated and
subjected to an engineering strain of greater than about 20%. The
film of the present invention has a predicted sound pressure level
over the frequency octave range of 2000 Hz-6300 Hz of less than
about 43 dB. Optionally, the film may comprise from about 1 wt. %
to about 30 wt. % of an elastomeric resin. The film of the present
invention may be used in absorbent articles and/or packages and/or
wrappers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a perspective view of an absorbent article made
according to the present invention.
[0013] FIG. 2 is a schematic representation of a sound measurement
device.
[0014] FIG. 3 is a schematic representation of a rotational
mechanism of the sound measurement device.
DETAILED DESCRIPTION OF THE INVENTION
[0015] As used herein, the following terms have the following
meanings:
[0016] As used herein, the term "absorbent articles" refers to
devices that absorb and contain body exudates, and, more
specifically, refers to devices that are placed against or in
proximity to the body of the wearer to absorb and contain the
various exudates discharged from the body. Absorbent articles may
include diapers, pants, training pants, an absorbent insert for a
diaper or pant, adult incontinence undergarments, feminine hygiene
products such as a sanitary napkin and a pantiliner, breast pads,
care mats, bibs, wound dressing products, and the like. As used
herein, the term "body fluids" or "body exudates" includes, but is
not limited to, urine, blood, vaginal discharges, breast milk,
sweat and fecal matter.
[0017] As used herein, the term "absorbent core" refers to the
component of the absorbent article that is primarily responsible
for fluid handling properties of the article, including acquiring,
transporting, distributing and storing body fluids. As such, the
absorbent core typically does not include the topsheet, backsheet
or outer cover of the absorbent article.
[0018] As used herein, the term "bonded" refers to different
materials being attached (cohesively or adhesively) in at least a
portion thereof. The attached portions may be random or may have a
pattern such as stripes, spirals, dots, and the like. The attached
portions may be located at the peripheries, throughout the surface
area, or both. Suitable attachment means known in the art may be
used, including but not limited to adhesives, heat, pressure,
crimping, ultrasonic, chemical (via hydrogen bonds or other
cohesive forces), mechanical (e.g., fasteners, entanglements),
hydraulic, vacuum and combinations thereof.
[0019] As used herein, the term "diaper" refers to an absorbent
article generally worn by infants and incontinent persons about the
lower torso so as to encircle the waist and legs of the wearer and
that is specifically adapted to receive and contain urinary and
fecal waste. As used herein, term "diaper" also includes "pants"
which is defined below.
[0020] As used herein, the term "disposable" is used in its
ordinary sense to mean an article that is disposed or discarded
after a limited number of usage events over varying lengths of
time, preferably less than about 20 events, more preferably less
than about 10 events, even more preferably less than about 5
events, and most preferably less than about 2 events.
[0021] As used herein, the term "joined" encompasses configurations
wherein an element is directly secured to the other element by
affixing the element directly to the other element, and
configurations wherein the element is indirectly secured to the
other element by affixing the element to intermediate member(s),
which in turn are affixed to the other element.
[0022] The term "longitudinal" refers to a direction running from a
waist edge to an opposing waist edge of the article and generally
parallel to the maximum linear dimension of the article. Directions
within .+-.45.degree. of the longitudinal direction are considered
to be "longitudinal".
[0023] The term "lateral" refers to a direction running from a side
edge to an opposing side edge of the article and generally at a
right angle to the longitudinal direction and in the same plane as
the longitudinal direction. Directions within .+-.45.degree. of the
lateral direction are considered to be "lateral".
[0024] As used herein, the term "nonwoven" refers to a web that has
a structure of individual fibers which are interlaid forming a
matrix, but not in an identifiable repeating manner. Nonwoven webs
may be formed by a variety of processes known to those skilled in
the art, for example, meltblowing, spunbonding, wet-laying,
air-laying, and various bonding-carding processes.
[0025] The terms "pant" or "training pant", as used herein, refer
to disposable garments having a waist opening and leg openings
designed for infant or adult wearers. A pant may be placed in
position on the wearer by inserting the wearer's legs into the leg
openings and sliding the pant into position about a wearer's lower
torso. A pant may be preformed by any suitable technique including,
but not limited to, joining together portions of the article using
refastenable and/or non-refastenable bonds (e.g., seam, weld,
adhesive, cohesive bond, fastener, etc.). A pant may be preformed
anywhere along the circumference of the article (e.g., side
fastened, front waist fastened). While the terms "pant" or "pants"
are used herein, pants are also commonly referred to as "closed
diapers", "prefastened diapers", "pull-on diapers", "training
pants" and "diaper-pants". Suitable pants are disclosed in U.S.
Pat. No. 5,246,433, issued to Hasse, et al. on Sep. 21, 1993; U.S.
Pat. No. 5,569,234, issued to Buell et al. on Oct. 29, 1996; U.S.
Pat. No. 6,120,487, issued to Ashton on Sep. 19, 2000; U.S. Pat.
No. 6,120,489, issued to Johnson et al. on Sep. 19, 2000; U.S. Pat.
No. 4,940,464, issued to Van Gompel et al. on Jul. 10, 1990; U.S.
Pat. No. 5,092,861, issued to Nomura et al. on Mar. 3, 1992; U.S.
Patent Publication No. 2003/0233082 A1, entitled "Highly Flexible
And Low Deformation Fastening Device", filed on Jun. 13, 2002; U.S.
Pat. No. 5,897,545, issued to Kline et al. on Apr. 27, 1999; U.S.
Pat. No. 5,957,908, issued to Kline et al on Sep. 28, 1999.
[0026] As used herein, the term "region" refers to a zone or an
area comprising a material being physically, chemically, or
visually distinguishable from surrounding or adjoining materials.
Various regions of materials may include transitional regions in
between. The regions may be positioned in the z-dimension or in the
xy-dimension. As used herein, the term "z-dimension" refers to the
dimension orthogonal to the length and width of the structure or
article. The z-dimension usually corresponds to the thickness of
the structure or article. As used herein, the term "xy-dimension"
refers to the plane orthogonal to the thickness of the member, core
or article when the member, core or article is in a flat-out state.
The xy-dimension usually corresponds to the length and width,
respectively, of the structure or article in a flat-out state.
[0027] The films of the present invention may have a basis weight
of from about 5 gsm to about 25 gsm; from about 15 gsm to about 25
gsm; from about 13 gsm to about 15 gsm; from about 12 gsm to about
14 gsm; from about 11 gsm to about 13 gsm; from about 8 gsm to
about 12 gsm; less than about 25 gsm; less than about 20 gsm; less
than about 15 gsm; greater than about 5 gsm; greater than about 8
gsm; greater than about 10 gsm. Basis weight measurements are made
prior to activation.
[0028] The films of the present invention may comprise from about
20 wt. % to about 80 wt. % of a polyolefin component. The
polyolefin component may be selected from the group consisting of
linear low density polyethylene polymers, low density polyethylene
polymers, high density polyethylene polymers, polypropylene
polymers, linear medium density polyethylene polymers, and mixtures
thereof. Developments towards optimization of production processes
of polyolefin resins may result in variants of the polyolefin
versions mentioned in this group, which may also be suitable for
this application. The polyolefin component may have a density of
from about 0.91 g/cm3 to about 0.95 g/cm3.
[0029] The polyolefin component may be any of the class of
thermoplastic polyolefin polymers or copolymers that are
processable into a film or for direct lamination by melt extrusion
onto the fibrous web. A number of thermoplastic polymers suitable
in the practice of the invention are olefin based polymers
including the most common ethylene or propylene based polymers such
as polyethylene, polypropylene, and copolymers such as ethylene
vinylacetate (EVA), ethylene methyl acrylate (EMA) and ethylene
acrylic acid (EAA), or blends of such polyolefins.
[0030] The particle component may be present in an amount of from
about 20 wt. % to about 50 wt. %; from about 35 wt. % to about 45
wt. %; from about 30 wt. % to about 40 wt. %; from about 25 wt. %
to about 35 wt. %; from about 25 wt. % to about 40 wt. %; less than
about 50 wt. %; less than about 45 wt. %; less than about 40 wt. %;
greater than about 20 wt. %; greater than about 25 wt. %; greater
than about 30 wt. % of the film.
[0031] The particle component may be selected from the group
consisting of friction reducing particles and opacifier particles.
The particle component may be selected from the group consisting of
CaCO3, TiO2, and combinations thereof. The particle component may
have a density of from about 1.8 g/cm3 to about 4.5 g/cm3. The
particle component may have a density of at least about 2 times the
density of the polyolefin component. Other particles may be used as
friction reducing particles, pigments, opacifiers or to provide
other benefits. Some examples are clays, silica, alumina, barium
sulfate, sodium carbonate, talc, magnesium sulfate, zeolites,
aluminum sulfate, diatomaceous earth, magnesium carbonate, barium
carbonate, kaolin, mica, carbon, calcium oxide, magnesium oxide and
aluminum hydroxide.
[0032] The film may be achieved by formulating a thermoplastic
polymer with suitable additives and pore-forming fillers to provide
an extrudate or film for embossing and lamination with the nonwoven
web. CaCO3 is a common filler. Microporous-formable compositions of
polyolefins, inorganic or organic pore-forming fillers and other
additives to make microporous sheet materials are known. This
method may be done in line and provides economies in manufacturing
and/or materials over known methods of making laminates. In
addition, as developed above, microporous-formable polymer
compositions may be obtained from blends of polymers such as a
blend of an alkanoyl polymer and polyvinyl alcohol as described in
U.S. Pat. No. 5,200,247. In addition, blends of an alkanoyl
polymer, destructured starch and an ethylene copolymer may be used
as the microporous-formable polymer composition as described in
U.S. Pat. No. 5,407,979. With these polymer blends, it is
unnecessary to use pore-forming fillers to provide microporosity
upon incremental stretching. Rather, the different polymer phases
in the film themselves, when the film is stretched at ambient or
room temperature, produce microvoids.
[0033] The films of the present invention may be activated and
subjected to an engineering strain of greater than about 15%;
greater than about 20%. The film may be subjected to an engineering
strain of from about 20% to about 70%. The film may be activated
with a 1.52 mm pitch tooling such that the depth of engagement of
the tooling is from about 0.508 mm to about 1.27 mm.
[0034] The films of the present invention may comprise an
elastomeric resin. The elastomeric resin may be present in an
amount of from about 1 wt. % to about 30 wt. %; from about 5 wt. %
to about 30 wt. %; from about 25 wt. % to about 35 wt. %; from
about 15 wt. % to about 20 wt. %; from about 15 wt. % to about 18
wt. %; from about 10 wt. % to about 15 wt. % from about 5 wt. % to
about 10 wt. %; less than about 35 wt. %; less than about 30 wt. %;
less than about 25 wt. %; less than about 20 wt. %; greater than
about 1 wt. %; greater than about 5 wt. %; greater than about 10
wt. %; greater than about 15 wt. % by weight of the film. The
elastomeric resin may be selected from the group consisting of
propylene based elastomer, propylene ethylene copolymer, styrenic
block copolymer resin. Some examples are poly(ethylene-butene),
poly(ethylene-hexene), poly(ethylene-octene),
poly(ethylene-propylene), poly(styrene-butadiene-styrene),
poly(styrene-isoprene-styrene),
poly(styrene-ethylene-butylene-styrene), poly(ester-ether),
poly(ether-amide), poly(ethylene-vinylacetate),
poly(ethylene-methylacrylate), poly(ethylene-acrylic acid),
poly(ethylene butylacrylate), polyurethane,
poly(ethylene-propylene-diene), ethylene-propylene rubber and
mixtures thereof. The elastomeric resin may have a degree of
crystallinity or end block content of from about 5% to about
30%.
[0035] Thermal stabilizers, UV stabilizers, antioxidants,
anti-blocking, lubricants, anti-static and slip agents and other
additives may be added to the formula to improve the stability of
the film when exposed to UV light, oxidizing agents, high
temperatures and/or to aid in the production or processing of the
resulting film. Examples of such additives include but are not
limited to fatty amines, phenolic and phosphite antioxidant
additives.
[0036] Films suitable for the present invention may be breathable
films. Breathable films are polymeric films containing filler
stretched to contain internal microporosities. Breathable films are
described in U.S. Pat. No. 4,472,328
[0037] The films of the present invention may be useful in
packaging films. Further, the films of the present invention may be
useful in absorbent articles or a component of an absorbent article
such as a backsheet, waistband, fastening members, and ears.
[0038] FIG. 1 depicts the absorbent articles of the present
invention, e.g., diaper(s) 20, which comprise a liquid pervious
topsheet 10, a backsheet 12 that is at least partially joined to
the topsheet 10, an absorbent core 18 disposed at least partially
between the topsheet 10 and the backsheet 12, a first cuff 16 along
a longitudinal edge 22 of the topsheet 10. In certain embodiments,
the absorbent articles may additionally include one or more
components selected from the group consisting of an outer cover,
side panels, an elastic feature, a fastening system, and
combinations thereof.
[0039] An outer cover (which may comprise the backsheet) forms the
chassis, onto which other components of the diaper are added to
form the unitary structure of the diaper. In alternative
embodiments, the article may be preformed by the manufacturer to
create a pant. The term "pant", as used herein, refers to
disposable garments having a waist opening and leg openings
designed for infant or adult wearers. A pant may be placed in
position on the wearer by inserting the wearer's legs into the leg
openings and sliding the pant into position about the wearer's
lower torso. A pant may be preformed by any suitable technique
including, but not limited to, joining together portions of the
article using refastenable and/or non-refastenable bonds (e.g.,
seam, weld, adhesive, cohesive bond, fastener, etc.). While the
term "pant" is used herein, pants are also commonly referred to as
"closed diapers", "prefastened diapers", "pull-on diapers",
"training pants" and "diaper-pants". Suitable pants are disclosed
in U.S. Pat. Nos. 5,246,433; 5,569,234, 6,120,487, 6,120,489,
4,940,464, 5,092,861, 5,897,545, 5,957,908, and U.S. Patent
Publication 2003/0233082A1.
[0040] The absorbent articles of the present invention comprise a
topsheet 10. The topsheet is preferably compliant, soft feeling,
and non-irritating to the wearer's skin. It can be elastically
stretchable in one or two directions. The topsheet has at least one
longitudinal edge 22 and in most instances has two. Further, the
topsheet is liquid pervious, permitting liquids (e.g., menses,
urine, and/or runny feces) to readily penetrate through its
thickness. A suitable topsheet can be manufactured from a wide
range of materials such as woven and nonwoven materials; apertured
or hydroformed thermoplastic films; porous foams; reticulated
foams; reticulated thermoplastic films; and thermoplastic scrims.
Suitable woven and nonwoven materials may comprise of natural
fibers such as wood or cotton fibers; synthetic fibers such as
polyester, polypropylene, or polyethylene fibers; or combinations
thereof. If the topsheet includes fibers, the fibers may be
spunbond, carded, wet-laid, meltblown, hydroentangled, or otherwise
processed as is known in the art. One suitable topsheet comprising
a web of staple-length polypropylene fibers is manufactured by
Veratec, Inc., a Division of International Paper Company, of
Walpole, Mass. under the designation P-8.
[0041] Preferred topsheet for use in the present invention are
selected from high loft nonwoven topsheets and apertured film
topsheet. Apertured film topsheet typically are pervious to bodily
exudates, yet non-absorbent, and have a reduced tendency to allow
fluids to pass back through and rewet the wearer's skin. Suitable
apertured films include those described in U.S. Pat. Nos.
5,628,097, 5,916,661, 6,545,197, 6,107,539, and PCT Patent
Publication WO 00/69382 A2.
[0042] Further, suitable topsheet materials for depositing solid
excretions thereon may include nonwovens having apertures, which
are at least in the portions that are aligned with the feces
deposition region of the article. Suitable apertured nonwovens are
described in more detail in U.S. Pat. Nos. 6,414,215, 5,342,338,
and 5,941,864 and U.S. Patent Publication 2002/017376. In another
embodiment of feces handling articles, such topsheets can be
combined with feces handling members, e.g., underlying such
topsheets, and which are further described in the abovementioned
patent documents.
[0043] Suitable formed film topsheets are described in U.S. Pat.
Nos. 3,929,135, 4,324,246, 4,342,314, 4,463,045, 5,006,394. Other
suitable topsheets may be made in accordance with U.S. Pat. Nos.
4,609,518 and 4,629,643. Such formed films are available from The
Procter & Gamble Company of Cincinnati, Ohio as "DRI-WEAVE" and
from Tredegar Corporation, based in Richmond, Va., as
"CLIFF-T."
[0044] Preferably, at least a portion of the topsheet is made of a
hydrophobic material or is treated to be hydrophobic in order to
isolate the wearer's skin from liquids contained in the absorbent
core. If the topsheet is made of a hydrophobic material, preferably
at least a portion of the upper surface of the topsheet is treated
to be hydrophilic so that liquids will transfer through the
topsheet more rapidly. The topsheet can be rendered hydrophilic by
treating it with a surfactant or by incorporating a surfactant into
the topsheet. Suitable methods for treating the topsheet with a
surfactant include spraying the topsheet material with the
surfactant and/or immersing the material into the surfactant. A
more detailed discussion of such a treatment and hydrophilicity is
contained in U.S. Pat. Nos. 4,988,344, 4,988,345, and 4,950,254. A
more detailed discussion of some suitable methods for incorporating
a surfactant in the topsheet 24 can be found in U.S. Statutory
Invention Registration No. H1670. Alternatively, the topsheet may
include an apertured web or film which is hydrophobic. This may be
accomplished by eliminating the hydrophilizing treatment step from
the production process and/or applying a hydrophobic treatment to
the topsheet, such as a polytetraflouroethylene compound like
SCOTCHGUARD or a hydrophobic lotion composition, as described
below. In such embodiments, it is preferred that the apertures be
large enough to allow the penetration of aqueous fluids like urine
without significant resistance.
[0045] Any portion of the topsheet may be coated with a lotion as
is known in the art. Examples of suitable lotions include those
described in U.S. Pat. Nos. 5,607,760, 5,609,587, 5,635,191,
5,643,588, and 5,9680,25. The lotion may function alone or in
combination with another agent as the hydrophobizing treatment
described above. The topsheet may also include or be treated with
antibacterial agents, some examples of which are disclosed in PCT
Publication No. WO 95/24173. Further, the topsheet, the outer cover
or any portion of the topsheet or outer cover may be embossed
and/or matte finished to provide a more cloth like appearance.
[0046] The topsheet may comprise one or more apertures to ease
penetration of exudates therethrough, such as urine and/or feces
(solid, semi-solid, or liquid). The size of at least the primary
aperture is important in achieving the desired waste encapsulation
performance. If the primary aperture is too small, the waste may
not pass through the aperture, either due to poor alignment of the
waste source and the aperture location or due to fecal masses
having a diameter greater than the aperture. If the aperture is too
large, the area of skin that may be contaminated by "rewet" (from
the article) is increased. Typically, the aperture should have an
area of between about 10 cm.sup.2 and about 50 cm.sup.2. The
aperture preferably has an area of between about 15 cm.sup.2 and 35
cm.sup.2.
[0047] Further, the topsheet may be fully or partially elasticated
or may be foreshortened so as to provide a void space between the
topsheet and the core. Exemplary structures including elasticized
or foreshortened topsheets are described in more detail in U.S.
Pat. Nos. 4,892,536, 4,990,147, 5,037,416, and 5,269,775.
[0048] The absorbent article further comprises a first cuff 16
along a longitudinal edge 22 of the topsheet 10. This first cuff 16
is useful for providing improved containment of liquids and other
body exudates. First cuffs 16 may also be referred to as outer leg
cuff, leg bands, side flaps, leg cuffs or elasticized cuffs. U.S.
Pat. No. 3,860,003 describes a disposable diaper which provides a
contractible leg opening having a side flap and one or more elastic
members to provide an elasticized leg cuff.
[0049] The first cuff 16 may be constructed in a number of
different configurations, including those described in U.S. Pat.
Nos. 3,860,003, 4,636,207, 4,695,278, 4,704,115, 4,795,454,
4,900,317, 4,909,803 (Reissued as U.S. RE34920), U.S. Pat. Nos.
5,085,654, 5,492,751, 6,476,288 and SIR H1630.
[0050] Additionally, an absorbent article of the present invention
may include one or more second cuffs that also provide improved
containment of liquids and other body exudates. Second cuffs may
also be referred to as barrier leg cuffs, inner leg cuffs or
"stand-up" elasticized flaps. U.S. Pat. Nos. 4,808,178 and
4,909,803 (Reissued as U.S. RE34920) describe disposable diapers
having "stand-up" elasticized flaps that improve the containment of
the leg regions.
[0051] First cuff and second cuff may both be provided by way of a
dual cuff, as exampled in U.S. Pat. Nos. 4,695,278 and 4,795,454.
Additional cuffs may be provided in an article of the present
invention as detailed in US Statutory Invention Registration
H1630.
[0052] The backsheet 12 may or may not be impervious to fluids
(e.g., menses, urine, and/or runny feces). Accordingly, one
embodiment of the backsheet is manufactured from a thin plastic
film, although other flexible liquid impervious or pervious
materials may also be used. As used herein, the term "flexible"
refers to materials which are compliant and will readily conform to
the general shape and contours of the human body. The backsheet 12
prevents the exudates absorbed and contained in the absorbent core
from wetting articles which contact the absorbent article such as
bedsheets, pants, pajamas and undergarments. The backsheet 12 may
thus comprise a woven or nonwoven material, polymeric films such as
thermoplastic films of polyethylene or polypropylene, and/or
composite materials such as a film-coated nonwoven material (i.e.,
having an inner film layer and an outer nonwoven layer). A suitable
backsheet 12 is a polyethylene film having a thickness of from
about 0.012 mm (0.5 mils) to about 0.051 mm (2.0 mils). Exemplary
polyethylene films are manufactured by Clopay Corporation of
Cincinnati, Ohio, under the designation BR-120 and BR-121 and by
Tredegar Film Products of Terre Haute, Ind., under the designation
XP-39385. The backsheet 12 is preferably embossed and/or
matte-finished to provide a more clothlike appearance. Further, the
backsheet 12 may permit vapors to escape from the absorbent core
(i.e., the backsheet is breathable) while still preventing exudates
from passing through the backsheet. The size of the backsheet 12 is
dictated by the size of the absorbent core 18 and the exact
absorbent article design selected.
[0053] The backsheet 12 and the topsheet 10 are positioned adjacent
a garment facing surface and a wearing facing surface,
respectively, of the absorbent core. The absorbent core 18 is
preferably joined with the topsheet 10, the backsheet 12, or both
in any manner as is known by attachment means such as those well
known in the art. However, embodiments of the present invention are
envisioned wherein portions of the entire absorbent core are
unattached to one or both of the topsheet 10 and the backsheet
12.
[0054] For example, the backsheet 12 and/or the topsheet 10 may be
secured to the absorbent core 18 or to each other by a uniform
continuous layer of adhesive, a patterned layer of adhesive, or an
array of separate lines, spirals, or spots of adhesive. Adhesives
which have been found to be satisfactory are manufactured by H. B.
Fuller Company of St. Paul, Minn. under the designation HL-1258 or
H-2031. The attachment means will preferably comprise an open
pattern network of filaments of adhesive as is disclosed in U.S.
Pat. No. 4,573,986. An exemplary attachment means of an open
pattern network of filaments comprises several lines of adhesive
filaments swirled into a spiral pattern such as illustrated by the
apparatus and method shown in U.S. Pat. Nos. 3,911,173, 4,785,996
and 4,842,666. Alternatively, the attachment means may comprise
heat bonds, pressure bonds, ultrasonic bonds, dynamic mechanical
bonds, or any other suitable attachment means or combinations of
these attachment means as are known in the art.
[0055] The backsheet 12 preferably includes an inner and outer
layer, each of which can be bonded to the other by a variety of
means known in the art, including thermal bonds, adhesive bonds,
ultrasonic lamination, or the like. Adhesive bonding can also be
accomplished using adhesive slot coating, high frequency
oscillation patterns, for example in swirl or spray patterns, and
other fine denier and/or high coverage application techniques.
Suitable laminate adhesives, which can be applied continuously or
intermittently, can be obtained from Findley Adhesives, Inc. or
from National Starch and Chemical Company.
[0056] The outer layer (or outer cover) of the backsheet can be
made in a variety of forms using different processes. For example,
the outer layer may be formed as a carded web, a bonded carded web,
a spunbond web, a needled fabric, a woven fabric, or the like to
provide a generally cloth-like texture to the wearer. Other
additives such as titanium dioxide can represent about 0.5% or
less, particularly about 0.3% or less, of the outer layer. In one
particular embodiment, the outer layer comprises a spunbond web
formed of about 99.5 to 100% polypropylene resin and about 0.5% or
less other additives. The outer layer is desirably a lightweight
material having a basis weight of about 15 to about 30 gsm and more
preferably from about 15 to about 25 gsm.
[0057] The articles of the present invention additionally comprise
one or more absorbent cores 18. The absorbent core 18 is at least
partially disposed between the topsheet 10 and the backsheet 12 and
may take on any size or shape that is compatible with the
disposable absorbent article. Exemplary absorbent structures for
use as the absorbent core of the present invention that have
achieved wide acceptance and commercial success are described in
U.S. Pat. Nos. 4,610,678, 4,673,402, and 4,888,231, and 4,834,735.
The absorbent core may further comprise the dual core system
containing an acquisition/distribution core of chemically stiffened
fibers positioned over an absorbent storage core as detailed in
U.S. Pat. Nos. 5,234,423 and 5,147,345.
[0058] In general, the absorbent core 18 is capable of absorbing or
retaining liquids (e.g., menses, urine, and/or other body
exudates). The absorbent core 18 is preferably compressible,
conformable, and non-irritating to the wearer's skin. The absorbent
core 18 may be manufactured in a wide variety of sizes and shapes
(e.g., rectangular, oval, hourglass, "T" shaped, dog bone,
asymmetric, etc.). The absorbent core 18 may include any of a wide
variety of liquid-absorbent materials commonly used in absorbent
articles, such as comminuted wood pulp, which is generally referred
to as airfelt. Examples of other suitable absorbent materials for
use in the absorbent core include creped cellulose wadding;
meltblown polymers including coform; chemically stiffened, modified
or cross-linked cellulosic fibers; synthetic fibers such as crimped
polyester fibers; peat moss; tissue including tissue wraps and
tissue laminates; absorbent foams; absorbent sponges;
superabsorbent polymers; absorbent gelling materials; or any
equivalent material or combinations of materials, or mixtures of
these.
[0059] As discussed herein "absorbent gelling materials" and
"superabsorbent polymers" are those materials that, upon contact
with aqueous fluids, such as bodily fluids, imbibes such fluids and
form hydrogels. These absorbent gelling materials are typically
capable of absorbing large quantities of aqueous bodily fluids, and
further capable of retaining such absorbed fluids under moderate
pressures. These absorbent gelling materials are typically in the
form of discrete, nonfibrous particles. Other forms, such as
fibers, foams, sheets, strips, or other macrostructures, are also
suitable for use herein. Suitable absorbent gelling materials in
the form of open cell foams may include those disclosed in U.S.
Pat. Nos. 3,563,243, 4,554,297, 4,740,520, and 5,260,345.
[0060] The configuration and construction of the absorbent core 18
may also be varied (e.g., the absorbent core may have varying
caliper zones and/or have a profile so as to be thicker in the
center; hydrophilic gradients; superabsorbent gradients; or lower
average density and lower average basis weight zones, e.g.,
acquisition zones; or may comprise one or more layers or
structures). The total absorbent capacity of the absorbent core 18
should, however, be compatible with the design loading and the
intended use of the absorbent article. Further, the size and
absorbent capacity of the absorbent core may be varied to
accommodate different uses such as diapers, incontinence pads,
pantiliners, regular sanitary napkins, and overnight sanitary
napkins, and to accommodate wearers ranging from infants to adults.
The absorbent core 18 can include other absorbent components that
are often used in absorbent articles, for example, a dusting layer,
a wicking or acquisition layer, or a secondary topsheet for
increasing the wearer's comfort.
[0061] In certain embodiments of the present invention, the
absorbent article may also include a sublayer disposed between the
topsheet 10 and the backsheet 12. The sublayer may be any material
or structure capable of accepting, storing or immobilizing bodily
exudates. Thus, the sublayer may include a single material or a
number of materials operatively associated with each other.
Further, the sublayer may be integral with another element of the
absorbent article or may be one or more separate elements joined
directly or indirectly with one or more elements of the article.
Further, the sublayer may include a structure that is separate from
the core or may include or be part of at least a portion of the
core.
[0062] Suitable materials for use as the sublayer may include large
cell open foams, macro-porous compression resistant nonwoven
highlofts, large size particulate forms of open and closed cell
foams (macro and/or microporous), highloft nonwovens, polyolefin,
polystyrene, polyurethane foams or particles, structures comprising
a multiplicity of vertically oriented looped strands of fibers,
absorbent core structures described above having punched holes or
depressions, and the like. One embodiment of a sublayer includes a
mechanical fastening loop landing element, having an uncompressed
thickness of about 1.5 millimeters available as XPL-7124 from the
3M Corporation of Minneapolis, Minn. Another embodiment includes a
6 denier, crimped and resin-bonded nonwoven highloft having a basis
weight of 110 grams per square meter and an uncompressed thickness
of 7.9 millimeters which is available from the Glit Company of
Wrens, Ga. Other suitable absorbent and nonabsorbent sublayers are
described in U.S. Pat. Nos. 6,680,422 and 5,941,864. Further, the
sublayer, or any portion thereof, may include or be coated with a
lotion or other known substances to add, enhance or change the
performance or other characteristics of the element.
[0063] Absorbent articles suitable for use as the present invention
include diapers, training pants, incontinence products, diaper
pants, disposable underwear, or the like. Suitable training pants
and diaper pants can have seamed side portions or refastenable side
portions. The present invention is particularly suited for use with
training pants or diaper pants to aid in toilet training Particular
diapers and training pants suitable for use with the present
invention are disclosed in U.S. Pat. Nos. 3,860,003, 4,636,207,
4,695,278, 4,704,115, 4,795,454, 4,900,317, 4,909,803 (Reissued as
U.S. RE34920), U.S. Pat. Nos. 5,085,654, 5,492,751, 6,476,288,
6,627,787, 5,507,760, 5,609,587, 5,635,191, 5,643,588, 6,118,041,
SIR H1630, U.S. Pat. Nos. 5,246,433, 5,769,838, 5,899,895,
5,899,896, and 6,120,487. Additional patents discussing suitable
training pants are disclosed earlier herein.
[0064] The article of the present invention may also comprise an
elastic waist feature that provides improved fit and containment;
and a fastening system which forms a side closure which maintains
the first waist region and the second waist region in an
overlapping configuration such that lateral tensions are maintained
around the circumference of the absorbent article to maintain the
absorbent article on the wearer. The absorbent article may also
comprise elasticized side panels (not shown) in the waist regions
and to provide an elastically extensible feature that provides a
more comfortable and contouring fit and more effective application
of the absorbent article. In certain embodiments, the elasticized
side panels are positioned such that a front and rear side panel
are joined to one another along their longitudinal edges. This
joining along the longitudinal edges of the panels may be permanent
or refastenable. For permanent joints, the panels may be adhered to
one another via ultrasonic bonding, high tack, adhesives, etc. For
refastenable joints, the panels may be joined via hook and loop
fasters, mild co-adhesive materials, low tack adhesives, etc.
[0065] The films of the present invention may have a predicted
sound pressure level over the frequency octave range of 2000
Hz-6300 Hz of less than about 43 dB, less than about 40 dB. The
film is tested using a testing mechanism comprised of a box (shown
in FIG. 2) having internal dimensions 192 mm wide by 203 mm deep by
198 mm in height. The box is made out of a rigid material able to
hold the weight of the rotational mechanism (shown in FIG. 3) and
stand the forces inflicted during testing without deformation. One
such suitable material is Lexan with a thickness of 12 mm. The box
has an opening at the top surface 401 large enough to allow
mounting film samples on the test brackets 411 and allow access to
the rotational mechanism for adjustments as needed. The box is
mounted on rubber footings 412, one on each corner of the bottom
surface of the box. The bottom of the box 410 is closed with a
rigid material to provide stability to the box.
[0066] A block with dimensions 13.1 cm long by 2.54 cm deep by 4 cm
tall serves at the supporting base 403 of the rotational mechanism
and it is attached to the front surface of the box 413. Base 403 is
made of Nylon or other similar material. Base 403 supports two pins
503 and 506 on which two nylon pulleys 501 and 507 are free to
rotate. The nylon pulleys are 7.5 cm in diameter and are connected
by a rubber belt 502 in a way that both pulleys rotate at the same
speed when the mechanism is activated. On the opposite end of pin
506, a wheel 402 is attached which is used to operate the
mechanism. A side view of the pulley 404 and the belt 405 are shown
in FIG. 2 as they are located in the box.
[0067] A mounting bracket 505 is attached to both pulleys at
attachment point 504. Point 504 is mounted on the pulley at a
radial distance of 25 mm from the pin 503 on pulley 501 and at a
radial distance of 25 mm from the pin 506 on pulley 507. Attached
to the mounting bracket 505 is clamp 411. Clamp 411 is at least 100
mm wide and has rubber pads 407 at the top and bottom of the clamp
to properly secure the test sample.
[0068] A second clamp identical to clamp 411 is mounted on a rod
408 which is located opposite to the first clamp. The rod 408 goes
thru a hole on the back surface of the box 414. The hole contains a
locking mechanism 409 which when disengaged allows the clamp 411 to
slide towards the back of the box 414 for sample loading and slide
towards the clamp mounted to the rotational mechanism for sample
testing.
[0069] Each clamp 411 has a piece of Lexan 406 with dimensions 100
mm long, 32 mm tall and 1.5 mm thick attached to the top jaw of the
clamp. A second piece of Lexan 415 with dimensions 100 mm long, 54
mm tall and 1.5 mm thick is attached to the bottom jaw of the
clamp. The means used to affix the plexiglass to the clamp will
vary depending on the clamp design selected and are not intended to
be prescribed. The attachments must be able to stand the stresses
induced during testing.
[0070] When the clamp 411 on mounting bracket 505 is moved to its
highest vertical position, it will be parallel with clamp 411
mounted on rod 408, but at a vertical distance of 10 mm. Test
samples loaded in this position will maintain both ends of the test
specimen parallel with each other.
[0071] When the mechanism is activated the first clamp 411 on
mounting bracket 505 will rotate in a circular path with a 23 mm
radius while the second clamp 411 on rod 408 stays stationary. To
load a film test specimen of 100 mm.times.100 mm unlock the locking
mechanism 409 to allow the rod 408 to move and set the distance
between the first and second clamps 411 to 67 mm. The first clamp
on mounting bracket 505 is moved to its highest vertical position
and the film test specimen is clamped with one edge in the first
clamp and the opposite edge in the second clamp. Once the test
specimen is secured in the clamps unlock the locking mechanism 409
and slide back the second clamp 411 mounted on rod 408 and set the
distance between clamps to 15 mm. Lock the locking mechanism to
prevent the second clamp from moving back.
[0072] The box 401 is placed inside an Audiometric test enclosure
with a Noise Isolation Class (NIC) equal or higher to 38 as
calculated in accordance with Classification ASTM E 413 Test Method
E596. The microphone with preamplifier of the sound meter is placed
in the test enclosure 50 mm above the second stationary clamp 411
and centered over the test sample. The analyst performing the test
steps into the audiometric test chamber with the sound meter and
closes the door of the chamber before setting the sound meter
instrument to collect data. The analyst turns the wheel of the
testing mechanism (402) at a rate of 1 revolution per second for 30
seconds and the sound pressure level is recorded by the sound meter
at the 1/3 octave frequency range between 2000 Hz and 6300 Hz.
After wards the analyst stops the sound meter data collection and
steps out the Audiometric test enclosure. The data from the sound
meter is later downloaded to a computer for analysis. It is
recommended to select an integrating sound meter which meets the
following standards: IEC 61672-1:2002, ANSI S1.4, ANSI S1.4. The
sound meter must have data logging software of spectral data and
1/3 octave band frequency analysis.
[0073] Embodiments of the film of the present disclosure are tested
and compared to a film not having low sound pressure level. All
samples produced are made with manually mixed batches of 4000 g.
The following resins are used for the trials.
[0074] Low Linear Density Polyethylene resin LLDPE LL3402.48 cast
hexane polyethylene with a thermal stabilizer additive manufactured
by ExxonMobil with a typical resin density of 0.942 g/cm3 and a
Melt Index of 2.0 g/10 min may be obtained from test method ASTM
D1238 may be tested at 190 C/2.16 Kg and a Peak melting temperature
of 128 C as reported in the manufacturer's technical data
sheet.
[0075] Low Density Polyethylene resin LD105.30 is a homopolymer
resin manufactured by ExxonMobil with a 1000 ppm Antiblock content
and a thermal stabilizer additive. The typical resin density is
0.923 g/cm3 and Melt Index of 2.0 g/10 min may be obtained from
test method ASTM D1238 may be tested at 190 C/2.16 Kg and a Peak
melting temperature of 111 C as reported in the manufacturer's
technical data sheet.
[0076] An olefinic elastomer may be the elastomeric resin.
Vistamaxx 6102 Propylene-based elastomer with 16% Ethylene content
manufactured by ExxonMobil using ExxonMobil Chemical's EXXPOL
catalyst. The typical resin density is 0.862 g/cm3 and Melt Index
of 1.5 g/10 min as reported in the manufacturer's technical data
sheet.
[0077] Titanium Oxide may be one of the particle additives. The
Titanium Oxide may be compounded by Ampacet in a masterbatch which
is commercially available under the tradename 11748 White PE MB.
The carrier resin used in the masterbatch is a Low Linear Density
Polyethylene with a Melt Index of 20 per ASTM D1238 190 C/2.16 Kg
and a density of 0.92 g/cm3 as reported by the manufacturer. The
final concentrate masterbatch may contain 70% Titanium Oxide and
may be compounded targeting a Melt Index Specification range of
13-23 per ASTM D1238 190 C/2.16 Kg.
[0078] Calcium Carbonate may be one of the particle additives. The
Calcium Carbonate may be compounded by Ampacet. A commercially
available masterbatch may be tested, tradename 1000175-N CaCO3 PE
MB with CaCO3 average particle size of 0.8 micron. The carrier
resin used in the masterbatches was a Low Linear Density
Polyethylene with a Melt Index of 20 per ASTM D1238 190 C/2.16 Kg
and a density of 0.92 g/cm3 as reported by the manufacturer.
[0079] Examples 1-3 may be produced in a Davis Standard small scale
cast extrusion line equipped with a 2.54 cm diameter single screw
extruder with 3 temperature zones and a 25.4 cm monolayer cast
extrusion die. The screw speed may be set to 60 RPM for Examples 1
and 2 and 45 RPM for Example 3. The temperatures at the extrusion
line may be maintained at the following set points below. The pull
roll may be chilled to about 18.degree. C. and the roll used may be
a smooth roll.
TABLE-US-00001 Temperature Set Temperature Set point for Example
point for Example Zone 1 and 2 (.degree. C.) 3 (.degree. C.) 1 190
200 2 200 230 3 210 230 Clamp 220 230 Hose 225 230 Die 230 230
TABLE-US-00002 1000175- 11748 LLDPE LDPE Vistamaxx N CaCO3 White
Basis Exam- 3402.48 105.30 6102 PE MB PE MB weight ple grams grams
grams grams grams (g/m2) 1 900 800 0 2300 0 17.33 2 800 800 400
1600 400 13.53 3 750 800 120 2130 200 16.68
[0080] The examples described above may be tested to determine a
predicted sound pressure level over the frequency octave range of
2000 Hz-6300 Hz.
[0081] The Particle % weight contained in a 4000 grams batch of
resin mix was calculated using the following formula:
Particle % weight=[(grams of master batch 1.times.percent particle
content on master batch 1)+(grams of master batch 2.times.percent
particle content on master batch 2)]/4000 grams
[0082] The Polyolefin % weight contained in a 4000 grams batch of
resin mix was calculated using the following formula:
Polyolefin % weight=(grams of resin 1+grams of resin 2)/4000
grams
[0083] The film examples are incrementally stretched by passing
them between intermesh rollers that stretch the films as the film
pass between the rollers. The intermesh rollers have teeth with a
spacing of 1.52 mm. This spacing is known as the pitch of the
tooling. The depth of engagement between the top and bottom
intermeshing rolls can be measured as the vertical distance from
the top of the tooth on the top roll to the top of the tooth on the
bottom roll next to it. The rollers are mounted on a frame and
connected by gears in such way that both the top and bottom rollers
rotate at the same speed. The pieces of film are manually fed
between the rollers which are turned manually to incrementally
stretch the film.
TABLE-US-00003 Elastomeric 1.52 mm pitch Average Particle %
Polyolefin % resin % tooing depth of SPL (dB) Example weight
Particle weight weight engagement (mm) 2000-6300 Hz 1 35 CaCO3 65 0
0 43.3 1a 35 CaCO3 65 0 0.508 36.2 1b 35 CaCO3 65 0 0.889 29.8 2 31
Blend of 59 10 0.000 38.2 CaCO3/TiO2 2a 31 Blend of 59 10 0.635
33.0 CaCO3/TiO2 2b 31 Blend of 59 10 0.762 31.7 CaCO3/TiO2 3 35
Blend of 62 3 0.000 48.7 CaCO3/TiO2 3a 35 Blend of 62 3 0.762 39.5
CaCO3/TiO2 3b 35 Blend of 62 3 0.889 32.2 CaCO3/TiO2 3c 35 Blend of
62 3 1.016 28.5 CaCO3/TiO2
[0084] With increasing depth of engagement, the film is
incrementally stretched and thinned out creating bands of thinner
film. With this process, the young's modulus of the film is
decreased in the direction the film was incrementally stretched and
therefore the noise produced by the film is decreased.
[0085] Various tooling pitch and the depth of engagement between
the top and bottom intermeshing rolls can provide the same
incremental stretching by applying in the stretched area the same
engineering strain. Engineering strain is the ratio between the
amount of deformation locally experienced by the film and the
original width of the area being incrementally stretched.
TABLE-US-00004 1.52 mm pitch tooling Calculated Depth of Engagement
Engineering (mm) Strain 0.508 20% 0.635 30% 0.762 41% 0.889 54%
1.016 67%
[0086] The calculated Engineering Strain is calculated using the
following formula:
Calculated Engineering Strain=[Stretched length-(tooling
Pitch/2)]/(tooling pitch/2);
where Stretched length=square root [(tooling pitch/2) 2+(depth of
engagement) 2].
[0087] Actual strains may be higher as it is known that the tooth
geometry and material and process of manufacturing of the
intermeshing rolls may affect the final strain experienced.
[0088] As evidenced in the data above, a film comprising: from
about 20 wt. % to about 85 wt. % of a polyolefin component and from
about 20 wt. % to about 45 wt. % of a particle component, the film
having a basis weight of from about 5 gsm to about 25 gsm, wherein
the film is activated and subjected to an engineering strain of
greater than about 20%; results the film having a predicted sound
pressure level over the frequency octave range of 2000 Hz-6300 Hz
of less than about 43 dB.
[0089] For comparison, the sound pressure level of some currently
marketed films was tested, and the ones tested did not have a
predicted sound pressure level over the frequency octave range of
2000 Hz-6300 Hz of less than about 43 dB. A film used in the
production of LUVS diapers manufactured by Procter and Gamble
produced in March 2012 has an average sound pressure level of 47.9
dB; a film used in the production of Pampers Baby Dry Diapers
manufactured by Procter and Gamble in February 2014 has an average
sound pressure level of 46.2 dB; a film used in the production of
wrappers for sanitary napkins manufactured by Procter and Gamble
produced in March 2012 has an average sound pressure level of 46.5
dB; a film from GOON premium size 2 diapers production Lot number
923212302 has an average sound pressure level of 45.3 dB. The film
was removed from the diaper by dissolving the adhesive gluing the
film to the core and nonwoven soft cover with a solvent.
[0090] The dimensions and values disclosed herein are not to be
understood as being strictly limited to the exact numerical values
recited. Instead, unless otherwise specified, each such dimension
is intended to mean both the recited value and a functionally
equivalent range surrounding that value. For example, a dimension
disclosed as "40 mm" is intended to mean "about 40 mm."
[0091] All documents cited in the Detailed Description of the
Invention are, in relevant part, incorporated herein by reference;
the citation of any document is not to be construed as an admission
that it is prior art with respect to the present invention. To the
extent that any meaning or definition of a term in this document
conflicts with any meaning or definition of the same term in a
document incorporated by reference, the meaning or definition
assigned to that term in this document shall govern.
[0092] While particular embodiments of the present invention have
been illustrated and described, it would be obvious to those
skilled in the art that various other changes and modifications can
be made without departing from the spirit and scope of the
invention. It is therefore intended to cover in the appended claims
all such changes and modifications that are within the scope of
this invention.
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